Efinaconazole: first global approval.

A non-lacquer 10% topical solution of efinaconazole, developed by Valeant Pharmaceuticals International, received its first global approval in Canada in October 2013 for the treatment of onychomycosis. The product is under regulatory review in the US and Japan. The mechanism of anti-fungal activity of efinaconazole, a small-molecule triazole compound, appears to be similar to that of other anti-fungal triazoles, namely ergosterol synthesis inhibition. In particular, it appears to inhibit 14α demethylase, an enzyme involved in the conversion of lanosterol to ergosterol, resulting in secondary degenerative changes. This article summarizes the milestones in the development of efinaconazole leading to this first approval for onychomycosis.